Begin with the decision.
“We need data on Nigeria” is a starting point, not a specification. Describe the decision that the information will support. For example: compare potential distribution locations in a defined group of cities.
Define the boundaries.
Name the geography, sector, unit of observation and reference period. Distinguish required fields from useful additions. A tighter scope makes source evaluation and coverage discussions much clearer.
Describe the workflow.
Explain who will use the result and in what form. An analyst may need a documented CSV; a product team may need structured JSON; a strategy team may need a report with traceable sources. Agree on delivery instead of assuming an API is available.
Write down the acceptance criteria.
Specify what would make the result usable: documented sources, clear definitions, a freshness threshold, known coverage gaps and agreed quality checks. Include the intended use so licensing can be assessed early.
Keep the brief open to evidence.
The first sourcing pass may reveal that a requested field is unavailable or unsuitable. Treat those findings as information for refining the scope, not a reason to hide the limitations.